* API: All pages list

[mediawiki.git] / includes / GlobalFunctions.php

<?php

/**
 * Global functions used everywhere
 * @package MediaWiki
 */

/**
 * Some globals and requires needed
 */

/**
 * Total number of articles
 * @global integer $wgNumberOfArticles
 */
$wgNumberOfArticles = -1; # Unset
/**
 * Total number of views
 * @global integer $wgTotalViews
 */
$wgTotalViews = -1;
/**
 * Total number of edits
 * @global integer $wgTotalEdits
 */
$wgTotalEdits = -1;


require_once( 'DatabaseFunctions.php' );
require_once( 'LogPage.php' );
require_once( 'normal/UtfNormalUtil.php' );
require_once( 'XmlFunctions.php' );

/**
 * Compatibility functions
 *
 * We more or less support PHP 5.0.x and up.
 * Re-implementations of newer functions or functions in non-standard
 * PHP extensions may be included here.
 */
if( !function_exists('iconv') ) {
        # iconv support is not in the default configuration and so may not be present.
        # Assume will only ever use utf-8 and iso-8859-1.
        # This will *not* work in all circumstances.
        function iconv( $from, $to, $string ) {
                if(strcasecmp( $from, $to ) == 0) return $string;
                if(strcasecmp( $from, 'utf-8' ) == 0) return utf8_decode( $string );
                if(strcasecmp( $to, 'utf-8' ) == 0) return utf8_encode( $string );
                return $string;
        }
}

# UTF-8 substr function based on a PHP manual comment
if ( !function_exists( 'mb_substr' ) ) {
        function mb_substr( $str, $start ) {
                preg_match_all( '/./us', $str, $ar );

                if( func_num_args() >= 3 ) {
                        $end = func_get_arg( 2 );
                        return join( '', array_slice( $ar[0], $start, $end ) );
                } else {
                        return join( '', array_slice( $ar[0], $start ) );
                }
        }
}

if ( !function_exists( 'array_diff_key' ) ) {
        /**
         * Exists in PHP 5.1.0+
         * Not quite compatible, two-argument version only
         * Null values will cause problems due to this use of isset()
         */
        function array_diff_key( $left, $right ) {
                $result = $left;
                foreach ( $left as $key => $value ) {
                        if ( isset( $right[$key] ) ) {
                                unset( $result[$key] );
                        }
                }
                return $result;
        }
}


/**
 * Wrapper for clone(), for compatibility with PHP4-friendly extensions.
 * PHP 5 won't let you declare a 'clone' function, even conditionally,
 * so it has to be a wrapper with a different name.
 */
function wfClone( $object ) {
        return clone( $object );
}

/**
 * Where as we got a random seed
 */
$wgRandomSeeded = false;

/**
 * Seed Mersenne Twister
 * No-op for compatibility; only necessary in PHP < 4.2.0
 */
function wfSeedRandom() {
        /* No-op */
}

/**
 * Get a random decimal value between 0 and 1, in a way
 * not likely to give duplicate values for any realistic
 * number of articles.
 *
 * @return string
 */
function wfRandom() {
        # The maximum random value is "only" 2^31-1, so get two random
        # values to reduce the chance of dupes
        $max = mt_getrandmax();
        $rand = number_format( (mt_rand() * $max + mt_rand())
                / $max / $max, 12, '.', '' );
        return $rand;
}

/**
 * We want / and : to be included as literal characters in our title URLs.
 * %2F in the page titles seems to fatally break for some reason.
 *
 * @param $s String:
 * @return string
*/
function wfUrlencode ( $s ) {
        $s = urlencode( $s );
        $s = preg_replace( '/%3[Aa]/', ':', $s );
        $s = preg_replace( '/%2[Ff]/', '/', $s );

        return $s;
}

/**
 * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 * In normal operation this is a NOP.
 *
 * Controlling globals:
 * $wgDebugLogFile - points to the log file
 * $wgProfileOnly - if set, normal debug messages will not be recorded.
 * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 *
 * @param $text String
 * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 */
function wfDebug( $text, $logonly = false ) {
        global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
        static $recursion = 0;

        # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
        if ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' && !$wgDebugRawPage ) {
                return;
        }

        if ( $wgDebugComments && !$logonly ) {
                if ( !isset( $wgOut ) ) {
                        return;
                }
                if ( !StubObject::isRealObject( $wgOut ) ) {
                        if ( $recursion ) {
                                return;
                        }
                        $recursion++;
                        $wgOut->_unstub();
                        $recursion--;
                }
                $wgOut->debug( $text );
        }
        if ( '' != $wgDebugLogFile && !$wgProfileOnly ) {
                # Strip unprintables; they can switch terminal modes when binary data
                # gets dumped, which is pretty annoying.
                $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
                @error_log( $text, 3, $wgDebugLogFile );
        }
}

/**
 * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 *
 * @param $logGroup String
 * @param $text String
 * @param $public Bool: whether to log the event in the public log if no private
 *                     log file is specified, (default true)
 */
function wfDebugLog( $logGroup, $text, $public = true ) {
        global $wgDebugLogGroups, $wgDBname;
        if( $text{strlen( $text ) - 1} != "\n" ) $text .= "\n";
        if( isset( $wgDebugLogGroups[$logGroup] ) ) {
                $time = wfTimestamp( TS_DB );
                @error_log( "$time $wgDBname: $text", 3, $wgDebugLogGroups[$logGroup] );
        } else if ( $public === true ) {
                wfDebug( $text, true );
        }
}

/**
 * Log for database errors
 * @param $text String: database error message.
 */
function wfLogDBError( $text ) {
        global $wgDBerrorLog;
        if ( $wgDBerrorLog ) {
                $host = trim(`hostname`);
                $text = date('D M j G:i:s T Y') . "\t$host\t".$text;
                error_log( $text, 3, $wgDBerrorLog );
        }
}

/**
 * @todo document
 */
function wfLogProfilingData() {
        global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
        global $wgProfiling, $wgUser;
        if ( $wgProfiling ) {
                $now = wfTime();
                $elapsed = $now - $wgRequestTime;
                $prof = wfGetProfilingOutput( $wgRequestTime, $elapsed );
                $forward = '';
                if( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) )
                        $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
                if( !empty( $_SERVER['HTTP_CLIENT_IP'] ) )
                        $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
                if( !empty( $_SERVER['HTTP_FROM'] ) )
                        $forward .= ' from ' . $_SERVER['HTTP_FROM'];
                if( $forward )
                        $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
                // Don't unstub $wgUser at this late stage just for statistics purposes
                if( StubObject::isRealObject($wgUser) && $wgUser->isAnon() )
                        $forward .= ' anon';
                $log = sprintf( "%s\t%04.3f\t%s\n",
                  gmdate( 'YmdHis' ), $elapsed,
                  urldecode( $_SERVER['REQUEST_URI'] . $forward ) );
                if ( '' != $wgDebugLogFile && ( $wgRequest->getVal('action') != 'raw' || $wgDebugRawPage ) ) {
                        error_log( $log . $prof, 3, $wgDebugLogFile );
                }
        }
}

/**
 * Check if the wiki read-only lock file is present. This can be used to lock
 * off editing functions, but doesn't guarantee that the database will not be
 * modified.
 * @return bool
 */
function wfReadOnly() {
        global $wgReadOnlyFile, $wgReadOnly;

        if ( !is_null( $wgReadOnly ) ) {
                return (bool)$wgReadOnly;
        }
        if ( '' == $wgReadOnlyFile ) {
                return false;
        }
        // Set $wgReadOnly for faster access next time
        if ( is_file( $wgReadOnlyFile ) ) {
                $wgReadOnly = file_get_contents( $wgReadOnlyFile );
        } else {
                $wgReadOnly = false;
        }
        return (bool)$wgReadOnly;
}


/**
 * Get a message from anywhere, for the current user language.
 *
 * Use wfMsgForContent() instead if the message should NOT
 * change depending on the user preferences.
 *
 * Note that the message may contain HTML, and is therefore
 * not safe for insertion anywhere. Some functions such as
 * addWikiText will do the escaping for you. Use wfMsgHtml()
 * if you need an escaped message.
 *
 * @param $key String: lookup key for the message, usually
 *    defined in languages/Language.php
 */
function wfMsg( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReal( $key, $args, true );
}

/**
 * Same as above except doesn't transform the message
 */
function wfMsgNoTrans( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReal( $key, $args, true, false );
}

/**
 * Get a message from anywhere, for the current global language
 * set with $wgLanguageCode.
 *
 * Use this if the message should NOT change  dependent on the
 * language set in the user's preferences. This is the case for
 * most text written into logs, as well as link targets (such as
 * the name of the copyright policy page). Link titles, on the
 * other hand, should be shown in the UI language.
 *
 * Note that MediaWiki allows users to change the user interface
 * language in their preferences, but a single installation
 * typically only contains content in one language.
 *
 * Be wary of this distinction: If you use wfMsg() where you should
 * use wfMsgForContent(), a user of the software may have to
 * customize over 70 messages in order to, e.g., fix a link in every
 * possible language.
 *
 * @param $key String: lookup key for the message, usually
 *    defined in languages/Language.php
 */
function wfMsgForContent( $key ) {
        global $wgForceUIMsgAsContentMsg;
        $args = func_get_args();
        array_shift( $args );
        $forcontent = true;
        if( is_array( $wgForceUIMsgAsContentMsg ) &&
                in_array( $key, $wgForceUIMsgAsContentMsg ) )
                $forcontent = false;
        return wfMsgReal( $key, $args, true, $forcontent );
}

/**
 * Same as above except doesn't transform the message
 */
function wfMsgForContentNoTrans( $key ) {
        global $wgForceUIMsgAsContentMsg;
        $args = func_get_args();
        array_shift( $args );
        $forcontent = true;
        if( is_array( $wgForceUIMsgAsContentMsg ) &&
                in_array( $key, $wgForceUIMsgAsContentMsg ) )
                $forcontent = false;
        return wfMsgReal( $key, $args, true, $forcontent, false );
}

/**
 * Get a message from the language file, for the UI elements
 */
function wfMsgNoDB( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReal( $key, $args, false );
}

/**
 * Get a message from the language file, for the content
 */
function wfMsgNoDBForContent( $key ) {
        global $wgForceUIMsgAsContentMsg;
        $args = func_get_args();
        array_shift( $args );
        $forcontent = true;
        if( is_array( $wgForceUIMsgAsContentMsg ) &&
                in_array( $key, $wgForceUIMsgAsContentMsg ) )
                $forcontent = false;
        return wfMsgReal( $key, $args, false, $forcontent );
}


/**
 * Really get a message
 * @return $key String: key to get.
 * @return $args
 * @return $useDB Boolean
 * @return String: the requested message.
 */
function wfMsgReal( $key, $args, $useDB = true, $forContent=false, $transform = true ) {
        $fname = 'wfMsgReal';

        $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
        $message = wfMsgReplaceArgs( $message, $args );
        return $message;
}

/**
 * This function provides the message source for messages to be edited which are *not* stored in the database.
 * @param $key String:
 */
function wfMsgWeirdKey ( $key ) {
        $subsource = str_replace ( ' ' , '_' , $key ) ;
        $source = wfMsgForContentNoTrans( $subsource ) ;
        if ( wfEmptyMsg( $subsource, $source) ) {
                # Try again with first char lower case
                $subsource = strtolower ( substr ( $subsource , 0 , 1 ) ) . substr ( $subsource , 1 ) ;
                $source = wfMsgForContentNoTrans( $subsource ) ;
        }
        if ( wfEmptyMsg( $subsource, $source ) ) {
                # Didn't work either, return blank text
                $source = "" ;
        }
        return $source ;
}

/**
 * Fetch a message string value, but don't replace any keys yet.
 * @param string $key
 * @param bool $useDB
 * @param bool $forContent
 * @return string
 * @private
 */
function wfMsgGetKey( $key, $useDB, $forContent = false, $transform = true ) {
        global $wgParser, $wgContLang, $wgMessageCache, $wgLang;

        if ( is_object( $wgMessageCache ) )
                $transstat = $wgMessageCache->getTransform();

        if( is_object( $wgMessageCache ) ) {
                if ( ! $transform )
                        $wgMessageCache->disableTransform();
                $message = $wgMessageCache->get( $key, $useDB, $forContent );
        } else {
                if( $forContent ) {
                        $lang = &$wgContLang;
                } else {
                        $lang = &$wgLang;
                }

                wfSuppressWarnings();

                if( is_object( $lang ) ) {
                        $message = $lang->getMessage( $key );
                } else {
                        $message = false;
                }
                wfRestoreWarnings();
                if($message === false)
                        $message = Language::getMessage($key);
                if ( $transform && strstr( $message, '{{' ) !== false ) {
                        $message = $wgParser->transformMsg($message, $wgMessageCache->getParserOptions() );
                }
        }

        if ( is_object( $wgMessageCache ) && ! $transform )
                $wgMessageCache->setTransform( $transstat );

        return $message;
}

/**
 * Replace message parameter keys on the given formatted output.
 *
 * @param string $message
 * @param array $args
 * @return string
 * @private
 */
function wfMsgReplaceArgs( $message, $args ) {
        # Fix windows line-endings
        # Some messages are split with explode("\n", $msg)
        $message = str_replace( "\r", '', $message );

        // Replace arguments
        if ( count( $args ) ) {
                if ( is_array( $args[0] ) ) {
                        foreach ( $args[0] as $key => $val ) {
                                $message = str_replace( '$' . $key, $val, $message );
                        }
                } else {
                        foreach( $args as $n => $param ) {
                                $replacementKeys['$' . ($n + 1)] = $param;
                        }
                        $message = strtr( $message, $replacementKeys );
                }
        }

        return $message;
}

/**
 * Return an HTML-escaped version of a message.
 * Parameter replacements, if any, are done *after* the HTML-escaping,
 * so parameters may contain HTML (eg links or form controls). Be sure
 * to pre-escape them if you really do want plaintext, or just wrap
 * the whole thing in htmlspecialchars().
 *
 * @param string $key
 * @param string ... parameters
 * @return string
 */
function wfMsgHtml( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key, true ) ), $args );
}

/**
 * Return an HTML version of message
 * Parameter replacements, if any, are done *after* parsing the wiki-text message,
 * so parameters may contain HTML (eg links or form controls). Be sure
 * to pre-escape them if you really do want plaintext, or just wrap
 * the whole thing in htmlspecialchars().
 *
 * @param string $key
 * @param string ... parameters
 * @return string
 */
function wfMsgWikiHtml( $key ) {
        global $wgOut;
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReplaceArgs( $wgOut->parse( wfMsgGetKey( $key, true ), /* can't be set to false */ true ), $args );
}

/**
 * Returns message in the requested format
 * @param string $key Key of the message
 * @param array $options Processing rules:
 *  <i>parse<i>: parses wikitext to html
 *  <i>parseinline<i>: parses wikitext to html and removes the surrounding p's added by parser or tidy
 *  <i>escape<i>: filters message trough htmlspecialchars
 *  <i>replaceafter<i>: parameters are substituted after parsing or escaping
 */
function wfMsgExt( $key, $options ) {
        global $wgOut, $wgMsgParserOptions, $wgParser;

        $args = func_get_args();
        array_shift( $args );
        array_shift( $args );

        if( !is_array($options) ) {
                $options = array($options);
        }

        $string = wfMsgGetKey( $key, true, false, false );

        if( !in_array('replaceafter', $options) ) {
                $string = wfMsgReplaceArgs( $string, $args );
        }

        if( in_array('parse', $options) ) {
                $string = $wgOut->parse( $string, true, true );
        } elseif ( in_array('parseinline', $options) ) {
                $string = $wgOut->parse( $string, true, true );
                $m = array();
                if( preg_match( "~^<p>(.*)\n?</p>$~", $string, $m ) ) {
                        $string = $m[1];
                }
        } elseif ( in_array('parsemag', $options) ) {
                global $wgTitle;
                $parser = new Parser();
                $parserOptions = new ParserOptions();
                $parserOptions->setInterfaceMessage( true );
                $parser->startExternalParse( $wgTitle, $parserOptions, OT_MSG );
                $string = $parser->transformMsg( $string, $parserOptions );
        }

        if ( in_array('escape', $options) ) {
                $string = htmlspecialchars ( $string );
        }

        if( in_array('replaceafter', $options) ) {
                $string = wfMsgReplaceArgs( $string, $args );
        }

        return $string;
}


/**
 * Just like exit() but makes a note of it.
 * Commits open transactions except if the error parameter is set
 *
 * @obsolete Please return control to the caller or throw an exception
 */
function wfAbruptExit( $error = false ){
        global $wgLoadBalancer;
        static $called = false;
        if ( $called ){
                exit( -1 );
        }
        $called = true;

        if( function_exists( 'debug_backtrace' ) ){ // PHP >= 4.3
                $bt = debug_backtrace();
                for($i = 0; $i < count($bt) ; $i++){
                        $file = isset($bt[$i]['file']) ? $bt[$i]['file'] : "unknown";
                        $line = isset($bt[$i]['line']) ? $bt[$i]['line'] : "unknown";
                        wfDebug("WARNING: Abrupt exit in $file at line $line\n");
                }
        } else {
                wfDebug('WARNING: Abrupt exit\n');
        }

        wfLogProfilingData();

        if ( !$error ) {
                $wgLoadBalancer->closeAll();
        }
        exit( -1 );
}

/**
 * @obsolete Please return control the caller or throw an exception
 */
function wfErrorExit() {
        wfAbruptExit( true );
}

/**
 * Print a simple message and die, returning nonzero to the shell if any.
 * Plain die() fails to return nonzero to the shell if you pass a string.
 * @param string $msg
 */
function wfDie( $msg='' ) {
        echo $msg;
        die( 1 );
}

/**
 * Throw a debugging exception. This function previously once exited the process, 
 * but now throws an exception instead, with similar results.
 *
 * @param string $msg Message shown when dieing.
 */
function wfDebugDieBacktrace( $msg = '' ) {
        throw new MWException( $msg );
}

/**
 * Fetch server name for use in error reporting etc.
 * Use real server name if available, so we know which machine
 * in a server farm generated the current page.
 * @return string
 */
function wfHostname() {
        if ( function_exists( 'posix_uname' ) ) {
                // This function not present on Windows
                $uname = @posix_uname();
        } else {
                $uname = false;
        }
        if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
                return $uname['nodename'];
        } else {
                # This may be a virtual server.
                return $_SERVER['SERVER_NAME'];
        }
}

        /**
         * Returns a HTML comment with the elapsed time since request.
         * This method has no side effects.
         * @return string
         */
        function wfReportTime() {
                global $wgRequestTime;

                $now = wfTime();
                $elapsed = $now - $wgRequestTime;

                $com = sprintf( "<!-- Served by %s in %01.3f secs. -->",
                  wfHostname(), $elapsed );
                return $com;
        }

function wfBacktrace() {
        global $wgCommandLineMode;
        if ( !function_exists( 'debug_backtrace' ) ) {
                return false;
        }

        if ( $wgCommandLineMode ) {
                $msg = '';
        } else {
                $msg = "<ul>\n";
        }
        $backtrace = debug_backtrace();
        foreach( $backtrace as $call ) {
                if( isset( $call['file'] ) ) {
                        $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
                        $file = $f[count($f)-1];
                } else {
                        $file = '-';
                }
                if( isset( $call['line'] ) ) {
                        $line = $call['line'];
                } else {
                        $line = '-';
                }
                if ( $wgCommandLineMode ) {
                        $msg .= "$file line $line calls ";
                } else {
                        $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
                }
                if( !empty( $call['class'] ) ) $msg .= $call['class'] . '::';
                $msg .= $call['function'] . '()';

                if ( $wgCommandLineMode ) {
                        $msg .= "\n";
                } else {
                        $msg .= "</li>\n";
                }
        }
        if ( $wgCommandLineMode ) {
                $msg .= "\n";
        } else {
                $msg .= "</ul>\n";
        }

        return $msg;
}


/* Some generic result counters, pulled out of SearchEngine */


/**
 * @todo document
 */
function wfShowingResults( $offset, $limit ) {
        global $wgLang;
        return wfMsg( 'showingresults', $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ) );
}

/**
 * @todo document
 */
function wfShowingResultsNum( $offset, $limit, $num ) {
        global $wgLang;
        return wfMsg( 'showingresultsnum', $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ), $wgLang->formatNum( $num ) );
}

/**
 * @todo document
 */
function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
        global $wgLang;
        $fmtLimit = $wgLang->formatNum( $limit );
        $prev = wfMsg( 'prevn', $fmtLimit );
        $next = wfMsg( 'nextn', $fmtLimit );

        if( is_object( $link ) ) {
                $title =& $link;
        } else {
                $title = Title::newFromText( $link );
                if( is_null( $title ) ) {
                        return false;
                }
        }

        if ( 0 != $offset ) {
                $po = $offset - $limit;
                if ( $po < 0 ) { $po = 0; }
                $q = "limit={$limit}&offset={$po}";
                if ( '' != $query ) { $q .= '&'.$query; }
                $plink = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$prev}</a>";
        } else { $plink = $prev; }

        $no = $offset + $limit;
        $q = 'limit='.$limit.'&offset='.$no;
        if ( '' != $query ) { $q .= '&'.$query; }

        if ( $atend ) {
                $nlink = $next;
        } else {
                $nlink = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$next}</a>";
        }
        $nums = wfNumLink( $offset, 20, $title, $query ) . ' | ' .
          wfNumLink( $offset, 50, $title, $query ) . ' | ' .
          wfNumLink( $offset, 100, $title, $query ) . ' | ' .
          wfNumLink( $offset, 250, $title, $query ) . ' | ' .
          wfNumLink( $offset, 500, $title, $query );

        return wfMsg( 'viewprevnext', $plink, $nlink, $nums );
}

/**
 * @todo document
 */
function wfNumLink( $offset, $limit, &$title, $query = '' ) {
        global $wgLang;
        if ( '' == $query ) { $q = ''; }
        else { $q = $query.'&'; }
        $q .= 'limit='.$limit.'&offset='.$offset;

        $fmtLimit = $wgLang->formatNum( $limit );
        $s = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$fmtLimit}</a>";
        return $s;
}

/**
 * @todo document
 * @todo FIXME: we may want to blacklist some broken browsers
 *
 * @return bool Whereas client accept gzip compression
 */
function wfClientAcceptsGzip() {
        global $wgUseGzip;
        if( $wgUseGzip ) {
                # FIXME: we may want to blacklist some broken browsers
                if( preg_match(
                        '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
                        $_SERVER['HTTP_ACCEPT_ENCODING'],
                        $m ) ) {
                        if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) return false;
                        wfDebug( " accepts gzip\n" );
                        return true;
                }
        }
        return false;
}

/**
 * Obtain the offset and limit values from the request string;
 * used in special pages
 *
 * @param $deflimit Default limit if none supplied
 * @param $optionname Name of a user preference to check against
 * @return array
 * 
 */
function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
        global $wgRequest;
        return $wgRequest->getLimitOffset( $deflimit, $optionname );
}

/**
 * Escapes the given text so that it may be output using addWikiText()
 * without any linking, formatting, etc. making its way through. This
 * is achieved by substituting certain characters with HTML entities.
 * As required by the callers, <nowiki> is not used. It currently does
 * not filter out characters which have special meaning only at the
 * start of a line, such as "*".
 *
 * @param string $text Text to be escaped
 */
function wfEscapeWikiText( $text ) {
        $text = str_replace(
                array( '[',     '|',      '\'',    'ISBN ',     'RFC ',     '://',     "\n=",     '{{' ),
                array( '&#91;', '&#124;', '&#39;', 'ISBN&#32;', 'RFC&#32;', '&#58;//', "\n&#61;", '&#123;&#123;' ),
                htmlspecialchars($text) );
        return $text;
}

/**
 * @todo document
 */
function wfQuotedPrintable( $string, $charset = '' ) {
        # Probably incomplete; see RFC 2045
        if( empty( $charset ) ) {
                global $wgInputEncoding;
                $charset = $wgInputEncoding;
        }
        $charset = strtoupper( $charset );
        $charset = str_replace( 'ISO-8859', 'ISO8859', $charset ); // ?

        $illegal = '\x00-\x08\x0b\x0c\x0e-\x1f\x7f-\xff=';
        $replace = $illegal . '\t ?_';
        if( !preg_match( "/[$illegal]/", $string ) ) return $string;
        $out = "=?$charset?Q?";
        $out .= preg_replace( "/([$replace])/e", 'sprintf("=%02X",ord("$1"))', $string );
        $out .= '?=';
        return $out;
}


/**
 * @todo document
 * @return float
 */
function wfTime() {
        return microtime(true);
}

/**
 * Sets dest to source and returns the original value of dest
 * If source is NULL, it just returns the value, it doesn't set the variable
 */
function wfSetVar( &$dest, $source ) {
        $temp = $dest;
        if ( !is_null( $source ) ) {
                $dest = $source;
        }
        return $temp;
}

/**
 * As for wfSetVar except setting a bit
 */
function wfSetBit( &$dest, $bit, $state = true ) {
        $temp = (bool)($dest & $bit );
        if ( !is_null( $state ) ) {
                if ( $state ) {
                        $dest |= $bit;
                } else {
                        $dest &= ~$bit;
                }
        }
        return $temp;
}

/**
 * This function takes two arrays as input, and returns a CGI-style string, e.g.
 * "days=7&limit=100". Options in the first array override options in the second.
 * Options set to "" will not be output.
 */
function wfArrayToCGI( $array1, $array2 = NULL )
{
        if ( !is_null( $array2 ) ) {
                $array1 = $array1 + $array2;
        }

        $cgi = '';
        foreach ( $array1 as $key => $value ) {
                if ( '' !== $value ) {
                        if ( '' != $cgi ) {
                                $cgi .= '&';
                        }
                        $cgi .= urlencode( $key ) . '=' . urlencode( $value );
                }
        }
        return $cgi;
}

/**
 * This is obsolete, use SquidUpdate::purge()
 * @deprecated
 */
function wfPurgeSquidServers ($urlArr) {
        SquidUpdate::purge( $urlArr );
}

/**
 * Windows-compatible version of escapeshellarg()
 * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
 * function puts single quotes in regardless of OS
 */
function wfEscapeShellArg( ) {
        $args = func_get_args();
        $first = true;
        $retVal = '';
        foreach ( $args as $arg ) {
                if ( !$first ) {
                        $retVal .= ' ';
                } else {
                        $first = false;
                }

                if ( wfIsWindows() ) {
                        // Escaping for an MSVC-style command line parser
                        // Ref: http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
                        // Double the backslashes before any double quotes. Escape the double quotes.
                        $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
                        $arg = '';
                        $delim = false;
                        foreach ( $tokens as $token ) {
                                if ( $delim ) {
                                        $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
                                } else {
                                        $arg .= $token;
                                }
                                $delim = !$delim;
                        }
                        // Double the backslashes before the end of the string, because
                        // we will soon add a quote
                        if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
                                $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
                        }

                        // Add surrounding quotes
                        $retVal .= '"' . $arg . '"';
                } else {
                        $retVal .= escapeshellarg( $arg );
                }
        }
        return $retVal;
}

/**
 * wfMerge attempts to merge differences between three texts.
 * Returns true for a clean merge and false for failure or a conflict.
 */
function wfMerge( $old, $mine, $yours, &$result ){
        global $wgDiff3;

        # This check may also protect against code injection in
        # case of broken installations.
        if(! file_exists( $wgDiff3 ) ){
                wfDebug( "diff3 not found\n" );
                return false;
        }

        # Make temporary files
        $td = wfTempDir();
        $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
        $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
        $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );

        fwrite( $oldtextFile, $old ); fclose( $oldtextFile );
        fwrite( $mytextFile, $mine ); fclose( $mytextFile );
        fwrite( $yourtextFile, $yours ); fclose( $yourtextFile );

        # Check for a conflict
        $cmd = $wgDiff3 . ' -a --overlap-only ' .
          wfEscapeShellArg( $mytextName ) . ' ' .
          wfEscapeShellArg( $oldtextName ) . ' ' .
          wfEscapeShellArg( $yourtextName );
        $handle = popen( $cmd, 'r' );

        if( fgets( $handle, 1024 ) ){
                $conflict = true;
        } else {
                $conflict = false;
        }
        pclose( $handle );

        # Merge differences
        $cmd = $wgDiff3 . ' -a -e --merge ' .
          wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
        $handle = popen( $cmd, 'r' );
        $result = '';
        do {
                $data = fread( $handle, 8192 );
                if ( strlen( $data ) == 0 ) {
                        break;
                }
                $result .= $data;
        } while ( true );
        pclose( $handle );
        unlink( $mytextName ); unlink( $oldtextName ); unlink( $yourtextName );

        if ( $result === '' && $old !== '' && $conflict == false ) {
                wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
                $conflict = true;
        }
        return ! $conflict;
}

/**
 * @todo document
 */
function wfVarDump( $var ) {
        global $wgOut;
        $s = str_replace("\n","<br />\n", var_export( $var, true ) . "\n");
        if ( headers_sent() || !@is_object( $wgOut ) ) {
                print $s;
        } else {
                $wgOut->addHTML( $s );
        }
}

/**
 * Provide a simple HTTP error.
 */
function wfHttpError( $code, $label, $desc ) {
        global $wgOut;
        $wgOut->disable();
        header( "HTTP/1.0 $code $label" );
        header( "Status: $code $label" );
        $wgOut->sendCacheControl();

        header( 'Content-type: text/html' );
        print "<html><head><title>" .
                htmlspecialchars( $label ) .
                "</title></head><body><h1>" .
                htmlspecialchars( $label ) .
                "</h1><p>" .
                htmlspecialchars( $desc ) .
                "</p></body></html>\n";
}

/**
 * Converts an Accept-* header into an array mapping string values to quality
 * factors
 */
function wfAcceptToPrefs( $accept, $def = '*/*' ) {
        # No arg means accept anything (per HTTP spec)
        if( !$accept ) {
                return array( $def => 1 );
        }

        $prefs = array();

        $parts = explode( ',', $accept );

        foreach( $parts as $part ) {
                # FIXME: doesn't deal with params like 'text/html; level=1'
                @list( $value, $qpart ) = explode( ';', $part );
                if( !isset( $qpart ) ) {
                        $prefs[$value] = 1;
                } elseif( preg_match( '/q\s*=\s*(\d*\.\d+)/', $qpart, $match ) ) {
                        $prefs[$value] = $match[1];
                }
        }

        return $prefs;
}

/**
 * Checks if a given MIME type matches any of the keys in the given
 * array. Basic wildcards are accepted in the array keys.
 *
 * Returns the matching MIME type (or wildcard) if a match, otherwise
 * NULL if no match.
 *
 * @param string $type
 * @param array $avail
 * @return string
 * @private
 */
function mimeTypeMatch( $type, $avail ) {
        if( array_key_exists($type, $avail) ) {
                return $type;
        } else {
                $parts = explode( '/', $type );
                if( array_key_exists( $parts[0] . '/*', $avail ) ) {
                        return $parts[0] . '/*';
                } elseif( array_key_exists( '*/*', $avail ) ) {
                        return '*/*';
                } else {
                        return NULL;
                }
        }
}

/**
 * Returns the 'best' match between a client's requested internet media types
 * and the server's list of available types. Each list should be an associative
 * array of type to preference (preference is a float between 0.0 and 1.0).
 * Wildcards in the types are acceptable.
 *
 * @param array $cprefs Client's acceptable type list
 * @param array $sprefs Server's offered types
 * @return string
 *
 * @todo FIXME: doesn't handle params like 'text/plain; charset=UTF-8'
 * XXX: generalize to negotiate other stuff
 */
function wfNegotiateType( $cprefs, $sprefs ) {
        $combine = array();

        foreach( array_keys($sprefs) as $type ) {
                $parts = explode( '/', $type );
                if( $parts[1] != '*' ) {
                        $ckey = mimeTypeMatch( $type, $cprefs );
                        if( $ckey ) {
                                $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
                        }
                }
        }

        foreach( array_keys( $cprefs ) as $type ) {
                $parts = explode( '/', $type );
                if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
                        $skey = mimeTypeMatch( $type, $sprefs );
                        if( $skey ) {
                                $combine[$type] = $sprefs[$skey] * $cprefs[$type];
                        }
                }
        }

        $bestq = 0;
        $besttype = NULL;

        foreach( array_keys( $combine ) as $type ) {
                if( $combine[$type] > $bestq ) {
                        $besttype = $type;
                        $bestq = $combine[$type];
                }
        }

        return $besttype;
}

/**
 * Array lookup
 * Returns an array where the values in the first array are replaced by the
 * values in the second array with the corresponding keys
 *
 * @return array
 */
function wfArrayLookup( $a, $b ) {
        return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
}

/**
 * Convenience function; returns MediaWiki timestamp for the present time.
 * @return string
 */
function wfTimestampNow() {
        # return NOW
        return wfTimestamp( TS_MW, time() );
}

/**
 * Reference-counted warning suppression
 */
function wfSuppressWarnings( $end = false ) {
        static $suppressCount = 0;
        static $originalLevel = false;

        if ( $end ) {
                if ( $suppressCount ) {
                        --$suppressCount;
                        if ( !$suppressCount ) {
                                error_reporting( $originalLevel );
                        }
                }
        } else {
                if ( !$suppressCount ) {
                        $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE ) );
                }
                ++$suppressCount;
        }
}

/**
 * Restore error level to previous value
 */
function wfRestoreWarnings() {
        wfSuppressWarnings( true );
}

# Autodetect, convert and provide timestamps of various types

/**
 * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
 */
define('TS_UNIX', 0);

/**
 * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
 */
define('TS_MW', 1);

/**
 * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
 */
define('TS_DB', 2);

/**
 * RFC 2822 format, for E-mail and HTTP headers
 */
define('TS_RFC2822', 3);

/**
 * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
 *
 * This is used by Special:Export
 */
define('TS_ISO_8601', 4);

/**
 * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
 *
 * @url http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
 *       DateTime tag and page 36 for the DateTimeOriginal and
 *       DateTimeDigitized tags.
 */
define('TS_EXIF', 5);

/**
 * Oracle format time.
 */
define('TS_ORACLE', 6);

/**
 * Postgres format time.
 */
define('TS_POSTGRES', 7);

/**
 * @param mixed $outputtype A timestamp in one of the supported formats, the
 *                          function will autodetect which format is supplied
 *                          and act accordingly.
 * @return string Time in the format specified in $outputtype
 */
function wfTimestamp($outputtype=TS_UNIX,$ts=0) {
        $uts = 0;
        $da = array();
        if ($ts==0) {
                $uts=time();
        } elseif (preg_match("/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D",$ts,$da)) {
                # TS_DB
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                            (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D",$ts,$da)) {
                # TS_EXIF
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                        (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D",$ts,$da)) {
                # TS_MW
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                            (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{1,13})$/D",$ts,$datearray)) {
                # TS_UNIX
                $uts = $ts;
        } elseif (preg_match('/^(\d{1,2})-(...)-(\d\d(\d\d)?) (\d\d)\.(\d\d)\.(\d\d)/', $ts, $da)) {
                # TS_ORACLE
                $uts = strtotime(preg_replace('/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
                                str_replace("+00:00", "UTC", $ts)));
        } elseif (preg_match('/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z$/', $ts, $da)) {
                # TS_ISO_8601
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                        (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)[\+\- ](\d\d)$/",$ts,$da)) {
                # TS_POSTGRES
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                (int)$da[2],(int)$da[3],(int)$da[1]);
        } else {
                # Bogus value; fall back to the epoch...
                wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
                $uts = 0;
        }


        switch($outputtype) {
                case TS_UNIX:
                        return $uts;
                case TS_MW:
                        return gmdate( 'YmdHis', $uts );
                case TS_DB:
                        return gmdate( 'Y-m-d H:i:s', $uts );
                case TS_ISO_8601:
                        return gmdate( 'Y-m-d\TH:i:s\Z', $uts );
                // This shouldn't ever be used, but is included for completeness
                case TS_EXIF:
                        return gmdate(  'Y:m:d H:i:s', $uts );
                case TS_RFC2822:
                        return gmdate( 'D, d M Y H:i:s', $uts ) . ' GMT';
                case TS_ORACLE:
                        return gmdate( 'd-M-y h.i.s A', $uts) . ' +00:00';
                case TS_POSTGRES:
                        return gmdate( 'Y-m-d H:i:s', $uts) . ' GMT';
                default:
                        throw new MWException( 'wfTimestamp() called with illegal output type.');
        }
}

/**
 * Return a formatted timestamp, or null if input is null.
 * For dealing with nullable timestamp columns in the database.
 * @param int $outputtype
 * @param string $ts
 * @return string
 */
function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
        if( is_null( $ts ) ) {
                return null;
        } else {
                return wfTimestamp( $outputtype, $ts );
        }
}

/**
 * Check if the operating system is Windows
 *
 * @return bool True if it's Windows, False otherwise.
 */
function wfIsWindows() {
        if (substr(php_uname(), 0, 7) == 'Windows') {
                return true;
        } else {
                return false;
        }
}

/**
 * Swap two variables
 */
function swap( &$x, &$y ) {
        $z = $x;
        $x = $y;
        $y = $z;
}

function wfGetCachedNotice( $name ) {
        global $wgOut, $parserMemc, $wgDBname;
        $fname = 'wfGetCachedNotice';
        wfProfileIn( $fname );
        
        $needParse = false;
        $notice = wfMsgForContent( $name );
        if( wfEmptyMsg( $name, $notice ) || $notice == '-' ) {
                wfProfileOut( $fname );
                return( false );
        }
        
        $cachedNotice = $parserMemc->get( $wgDBname . ':' . $name );
        if( is_array( $cachedNotice ) ) {
                if( md5( $notice ) == $cachedNotice['hash'] ) {
                        $notice = $cachedNotice['html'];
                } else {
                        $needParse = true;
                }
        } else {
                $needParse = true;
        }
        
        if( $needParse ) {
                if( is_object( $wgOut ) ) {
                        $parsed = $wgOut->parse( $notice );
                        $parserMemc->set( $wgDBname . ':' . $name, array( 'html' => $parsed, 'hash' => md5( $notice ) ), 600 );
                        $notice = $parsed;
                } else {
                        wfDebug( 'wfGetCachedNotice called for ' . $name . ' with no $wgOut available' );
                        $notice = '';
                }
        }
        
        wfProfileOut( $fname );
        return $notice;
}

function wfGetNamespaceNotice() {
        global $wgTitle;
        
        # Paranoia
        if ( !isset( $wgTitle ) || !is_object( $wgTitle ) )
                return "";

        $fname = 'wfGetNamespaceNotice';
        wfProfileIn( $fname );
        
        $key = "namespacenotice-" . $wgTitle->getNsText();
        $namespaceNotice = wfGetCachedNotice( $key );
        if ( $namespaceNotice && substr ( $namespaceNotice , 0 ,7 ) != "<p>&lt;" ) {
                 $namespaceNotice = '<div id="namespacebanner">' . $namespaceNotice . "</div>";
        } else {
                $namespaceNotice = "";
        }

        wfProfileOut( $fname );
        return $namespaceNotice;
}

function wfGetSiteNotice() {
        global $wgUser, $wgSiteNotice;
        $fname = 'wfGetSiteNotice';
        wfProfileIn( $fname );
        $siteNotice = '';       
        
        if( wfRunHooks( 'SiteNoticeBefore', array( &$siteNotice ) ) ) {
                if( is_object( $wgUser ) && $wgUser->isLoggedIn() ) {
                        $siteNotice = wfGetCachedNotice( 'sitenotice' );
                        $siteNotice = !$siteNotice ? $wgSiteNotice : $siteNotice;
                } else {
                        $anonNotice = wfGetCachedNotice( 'anonnotice' );
                        if( !$anonNotice ) {
                                $siteNotice = wfGetCachedNotice( 'sitenotice' );
                                $siteNotice = !$siteNotice ? $wgSiteNotice : $siteNotice;
                        } else {
                                $siteNotice = $anonNotice;
                        }
                }
        }

        wfRunHooks( 'SiteNoticeAfter', array( &$siteNotice ) );
        wfProfileOut( $fname );
        return $siteNotice;
}

/** Global singleton instance of MimeMagic. This is initialized on demand,
* please always use the wfGetMimeMagic() function to get the instance.
*
* @private
*/
$wgMimeMagic= NULL;

/** Factory functions for the global MimeMagic object.
* This function always returns the same singleton instance of MimeMagic.
* That objects will be instantiated on the first call to this function.
* If needed, the MimeMagic.php file is automatically included by this function.
* @return MimeMagic the global MimeMagic objects.
*/
function &wfGetMimeMagic() {
        global $wgMimeMagic;

        if (!is_null($wgMimeMagic)) {
                return $wgMimeMagic;
        }

        if (!class_exists("MimeMagic")) {
                #include on demand
                require_once("MimeMagic.php");
        }

        $wgMimeMagic= new MimeMagic();

        return $wgMimeMagic;
}


/**
 * Tries to get the system directory for temporary files.
 * The TMPDIR, TMP, and TEMP environment variables are checked in sequence,
 * and if none are set /tmp is returned as the generic Unix default.
 *
 * NOTE: When possible, use the tempfile() function to create temporary
 * files to avoid race conditions on file creation, etc.
 *
 * @return string
 */
function wfTempDir() {
        foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
                $tmp = getenv( $var );
                if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
                        return $tmp;
                }
        }
        # Hope this is Unix of some kind!
        return '/tmp';
}

/**
 * Make directory, and make all parent directories if they don't exist
 */
function wfMkdirParents( $fullDir, $mode = 0777 ) {
        if ( strval( $fullDir ) === '' ) {
                return true;
        }
        
        # Go back through the paths to find the first directory that exists
        $currentDir = $fullDir;
        $createList = array();
        while ( strval( $currentDir ) !== '' && !file_exists( $currentDir ) ) { 
                # Strip trailing slashes
                $currentDir = rtrim( $currentDir, '/\\' );

                # Add to create list
                $createList[] = $currentDir;

                # Find next delimiter searching from the end
                $p = max( strrpos( $currentDir, '/' ), strrpos( $currentDir, '\\' ) );
                if ( $p === false ) {
                        $currentDir = false;
                } else {
                        $currentDir = substr( $currentDir, 0, $p );
                }
        }
        
        if ( count( $createList ) == 0 ) {
                # Directory specified already exists
                return true;
        } elseif ( $currentDir === false ) {
                # Went all the way back to root and it apparently doesn't exist
                return false;
        }
        
        # Now go forward creating directories
        $createList = array_reverse( $createList );
        foreach ( $createList as $dir ) {
                # use chmod to override the umask, as suggested by the PHP manual
                if ( !mkdir( $dir, $mode ) || !chmod( $dir, $mode ) ) {
                        return false;
                } 
        }
        return true;
}

/**
 * Increment a statistics counter
 */
 function wfIncrStats( $key ) {
         global $wgDBname, $wgMemc;
         $key = "$wgDBname:stats:$key";
         if ( is_null( $wgMemc->incr( $key ) ) ) {
                 $wgMemc->add( $key, 1 );
         }
 }

/**
 * @param mixed $nr The number to format
 * @param int $acc The number of digits after the decimal point, default 2
 * @param bool $round Whether or not to round the value, default true
 * @return float
 */
function wfPercent( $nr, $acc = 2, $round = true ) {
        $ret = sprintf( "%.${acc}f", $nr );
        return $round ? round( $ret, $acc ) . '%' : "$ret%";
}

/**
 * Encrypt a username/password.
 *
 * @param string $userid ID of the user
 * @param string $password Password of the user
 * @return string Hashed password
 */
function wfEncryptPassword( $userid, $password ) {
        global $wgPasswordSalt;
        $p = md5( $password);

        if($wgPasswordSalt)
                return md5( "{$userid}-{$p}" );
        else
                return $p;
}

/**
 * Appends to second array if $value differs from that in $default
 */
function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
        if ( is_null( $changed ) ) {
                throw new MWException('GlobalFunctions::wfAppendToArrayIfNotDefault got null');
        }
        if ( $default[$key] !== $value ) {
                $changed[$key] = $value;
        }
}

/**
 * Since wfMsg() and co suck, they don't return false if the message key they
 * looked up didn't exist but a XHTML string, this function checks for the
 * nonexistance of messages by looking at wfMsg() output
 *
 * @param $msg      The message key looked up
 * @param $wfMsgOut The output of wfMsg*()
 * @return bool
 */
function wfEmptyMsg( $msg, $wfMsgOut ) {
        return $wfMsgOut === "&lt;$msg&gt;";
}

/**
 * Find out whether or not a mixed variable exists in a string
 *
 * @param mixed  needle
 * @param string haystack
 * @return bool
 */
function in_string( $needle, $str ) {
        return strpos( $str, $needle ) !== false;
}

function wfSpecialList( $page, $details ) {
        global $wgContLang;
        $details = $details ? ' ' . $wgContLang->getDirMark() . "($details)" : "";
        return $page . $details;
}

/**
 * Returns a regular expression of url protocols
 *
 * @return string
 */
function wfUrlProtocols() {
        global $wgUrlProtocols;

        // Support old-style $wgUrlProtocols strings, for backwards compatibility
        // with LocalSettings files from 1.5
        if ( is_array( $wgUrlProtocols ) ) {
                $protocols = array();
                foreach ($wgUrlProtocols as $protocol)
                        $protocols[] = preg_quote( $protocol, '/' );

                return implode( '|', $protocols );
        } else {
                return $wgUrlProtocols;
        }
}

/**
 * Execute a shell command, with time and memory limits mirrored from the PHP
 * configuration if supported.
 * @param $cmd Command line, properly escaped for shell.
 * @param &$retval optional, will receive the program's exit code.
 *                 (non-zero is usually failure)
 * @return collected stdout as a string (trailing newlines stripped)
 */
function wfShellExec( $cmd, &$retval=null ) {
        global $IP, $wgMaxShellMemory;
        
        if( ini_get( 'safe_mode' ) ) {
                wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
                $retval = 1;
                return "Unable to run external programs in safe mode.";
        }

        if ( php_uname( 's' ) == 'Linux' ) {
                $time = ini_get( 'max_execution_time' );
                $mem = intval( $wgMaxShellMemory );

                if ( $time > 0 && $mem > 0 ) {
                        $script = "$IP/bin/ulimit.sh";
                        if ( is_executable( $script ) ) {
                                $cmd = escapeshellarg( $script ) . " $time $mem $cmd";
                        }
                }
        } elseif ( php_uname( 's' ) == 'Windows NT' ) {
                # This is a hack to work around PHP's flawed invocation of cmd.exe
                # http://news.php.net/php.internals/21796
                $cmd = '"' . $cmd . '"';
        }
        wfDebug( "wfShellExec: $cmd\n" );
        
        $output = array();
        $retval = 1; // error by default?
        $lastline = exec( $cmd, $output, $retval );
        return implode( "\n", $output );
        
}

/**
 * This function works like "use VERSION" in Perl, the program will die with a
 * backtrace if the current version of PHP is less than the version provided
 *
 * This is useful for extensions which due to their nature are not kept in sync
 * with releases, and might depend on other versions of PHP than the main code
 *
 * Note: PHP might die due to parsing errors in some cases before it ever
 *       manages to call this function, such is life
 *
 * @see perldoc -f use
 *
 * @param mixed $version The version to check, can be a string, an integer, or
 *                       a float
 */
function wfUsePHP( $req_ver ) {
        $php_ver = PHP_VERSION;

        if ( version_compare( $php_ver, (string)$req_ver, '<' ) )
                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
}

/**
 * This function works like "use VERSION" in Perl except it checks the version
 * of MediaWiki, the program will die with a backtrace if the current version
 * of MediaWiki is less than the version provided.
 *
 * This is useful for extensions which due to their nature are not kept in sync
 * with releases
 *
 * @see perldoc -f use
 *
 * @param mixed $version The version to check, can be a string, an integer, or
 *                       a float
 */
function wfUseMW( $req_ver ) {
        global $wgVersion;

        if ( version_compare( $wgVersion, (string)$req_ver, '<' ) )
                throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
}

/**
 * Escape a string to make it suitable for inclusion in a preg_replace()
 * replacement parameter.
 *
 * @param string $string
 * @return string
 */
function wfRegexReplacement( $string ) {
        $string = str_replace( '\\', '\\\\', $string );
        $string = str_replace( '$', '\\$', $string );
        return $string;
}

/**
 * Return the final portion of a pathname.
 * Reimplemented because PHP5's basename() is buggy with multibyte text.
 * http://bugs.php.net/bug.php?id=33898
 *
 * PHP's basename() only considers '\' a pathchar on Windows and Netware.
 * We'll consider it so always, as we don't want \s in our Unix paths either.
 * 
 * @param string $path
 * @return string
 */
function wfBaseName( $path ) {
        if( preg_match( '#([^/\\\\]*)[/\\\\]*$#', $path, $matches ) ) {
                return $matches[1];
        } else {
                return '';
        }
}

/**
 * Make a URL index, appropriate for the el_index field of externallinks.
 */
function wfMakeUrlIndex( $url ) {
        wfSuppressWarnings();
        $bits = parse_url( $url );
        wfRestoreWarnings();
        if ( !$bits || $bits['scheme'] !== 'http' ) {
                return false;
        }
        // Reverse the labels in the hostname, convert to lower case
        $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
        // Add an extra dot to the end
        if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
                $reversedHost .= '.';
        }
        // Reconstruct the pseudo-URL
        $index = "http://$reversedHost";
        // Leave out user and password. Add the port, path, query and fragment
        if ( isset( $bits['port'] ) )      $index .= ':' . $bits['port'];
        if ( isset( $bits['path'] ) ) {
                $index .= $bits['path'];
        } else {
                $index .= '/';
        }
        if ( isset( $bits['query'] ) )     $index .= '?' . $bits['query'];
        if ( isset( $bits['fragment'] ) )  $index .= '#' . $bits['fragment'];
        return $index;
}

/**
 * Do any deferred updates and clear the list
 * TODO: This could be in Wiki.php if that class made any sense at all
 */
function wfDoUpdates()
{
        global $wgPostCommitUpdateList, $wgDeferredUpdateList;
        foreach ( $wgDeferredUpdateList as $update ) {
                $update->doUpdate();
        }
        foreach ( $wgPostCommitUpdateList as $update ) {
                $update->doUpdate();
        }
        $wgDeferredUpdateList = array();
        $wgPostCommitUpdateList = array();
}

/**
 * More or less "markup-safe" explode()
 * Ignores any instances of the separator inside <...>
 * @param string $separator
 * @param string $text
 * @return array
 */
function wfExplodeMarkup( $separator, $text ) {
        $placeholder = "\x00";
        
        // Just in case...
        $text = str_replace( $placeholder, '', $text );
        
        // Trim stuff
        $replacer = new ReplacerCallback( $separator, $placeholder );
        $cleaned = preg_replace_callback( '/(<.*?>)/', array( $replacer, 'go' ), $text );
        
        $items = explode( $separator, $cleaned );
        foreach( $items as $i => $str ) {
                $items[$i] = str_replace( $placeholder, $separator, $str );
        }
        
        return $items;
}

class ReplacerCallback {
        function ReplacerCallback( $from, $to ) {
                $this->from = $from;
                $this->to = $to;
        }
        
        function go( $matches ) {
                return str_replace( $this->from, $this->to, $matches[1] );
        }
}


/**
 * Convert an arbitrarily-long digit string from one numeric base
 * to another, optionally zero-padding to a minimum column width.
 *
 * Supports base 2 through 36; digit values 10-36 are represented
 * as lowercase letters a-z. Input is case-insensitive.
 *
 * @param $input string of digits
 * @param $sourceBase int 2-36
 * @param $destBase int 2-36
 * @param $pad int 1 or greater
 * @return string or false on invalid input
 */
function wfBaseConvert( $input, $sourceBase, $destBase, $pad=1 ) {
        if( $sourceBase < 2 ||
                $sourceBase > 36 ||
                $destBase < 2 ||
                $destBase > 36 ||
                $pad < 1 ||
                $sourceBase != intval( $sourceBase ) ||
                $destBase != intval( $destBase ) ||
                $pad != intval( $pad ) ||
                !is_string( $input ) ||
                $input == '' ) {
                return false;
        }
        
        $digitChars = '0123456789abcdefghijklmnopqrstuvwxyz';
        $inDigits = array();
        $outChars = '';
        
        // Decode and validate input string
        $input = strtolower( $input );
        for( $i = 0; $i < strlen( $input ); $i++ ) {
                $n = strpos( $digitChars, $input{$i} );
                if( $n === false || $n > $sourceBase ) {
                        return false;
                }
                $inDigits[] = $n;
        }
        
        // Iterate over the input, modulo-ing out an output digit
        // at a time until input is gone.
        while( count( $inDigits ) ) {
                $work = 0;
                $workDigits = array();
                
                // Long division...
                foreach( $inDigits as $digit ) {
                        $work *= $sourceBase;
                        $work += $digit;
                        
                        if( $work < $destBase ) {
                                // Gonna need to pull another digit.
                                if( count( $workDigits ) ) {
                                        // Avoid zero-padding; this lets us find
                                        // the end of the input very easily when
                                        // length drops to zero.
                                        $workDigits[] = 0;
                                }
                        } else {
                                // Finally! Actual division!
                                $workDigits[] = intval( $work / $destBase );
                                
                                // Isn't it annoying that most programming languages
                                // don't have a single divide-and-remainder operator,
                                // even though the CPU implements it that way?
                                $work = $work % $destBase;
                        }
                }
                
                // All that division leaves us with a remainder,
                // which is conveniently our next output digit.
                $outChars .= $digitChars[$work];
                
                // And we continue!
                $inDigits = $workDigits;
        }
        
        while( strlen( $outChars ) < $pad ) {
                $outChars .= '0';
        }
        
        return strrev( $outChars );
}

/**
 * Create an object with a given name and an array of construct parameters
 * @param string $name
 * @param array $p parameters
 */
function wfCreateObject( $name, $p ){
        $p = array_values( $p );
        switch ( count( $p ) ) {
                case 0:
                        return new $name;
                case 1:
                        return new $name( $p[0] );
                case 2:
                        return new $name( $p[0], $p[1] );
                case 3:
                        return new $name( $p[0], $p[1], $p[2] );
                case 4:
                        return new $name( $p[0], $p[1], $p[2], $p[3] );
                case 5:
                        return new $name( $p[0], $p[1], $p[2], $p[3], $p[4] );
                case 6:
                        return new $name( $p[0], $p[1], $p[2], $p[3], $p[4], $p[5] );
                default:
                        throw new MWException( "Too many arguments to construtor in wfCreateObject" );
        }
}

/**
 * Aliases for modularized functions
 */
function wfGetHTTP( $url, $timeout = 'default' ) { 
        return Http::get( $url, $timeout ); 
}
function wfIsLocalURL( $url ) { 
        return Http::isLocalURL( $url ); 
}

/**
 * Initialise php session
 */
function wfSetupSession() {
        global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain;
        if( $wgSessionsInMemcached ) {
                require_once( 'MemcachedSessions.php' );
        } elseif( 'files' != ini_get( 'session.save_handler' ) ) {
                # If it's left on 'user' or another setting from another
                # application, it will end up failing. Try to recover.
                ini_set ( 'session.save_handler', 'files' );
        }
        session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain );
        session_cache_limiter( 'private, must-revalidate' );
        @session_start();
}

/**
 * Get an object from the precompiled serialized directory
 *
 * @return mixed The variable on success, false on failure
 */
function wfGetPrecompiledData( $name ) {
        global $IP;

        $file = "$IP/serialized/$name";
        if ( file_exists( $file ) ) {
                $blob = file_get_contents( $file );
                if ( $blob ) {
                        return unserialize( $blob );
                }
        }
        return false;
}

function wfGetCaller( $level = 2 ) {
        $backtrace = debug_backtrace();
        if ( isset( $backtrace[$level] ) ) {
                if ( isset( $backtrace[$level]['class'] ) ) {
                        $caller = $backtrace[$level]['class'] . '::' . $backtrace[$level]['function'];
                } else {
                        $caller = $backtrace[$level]['function'];
                }
        } else {
                $caller = 'unknown';
        }
        return $caller;
}

/** Return a string consisting all callers in stack, somewhat useful sometimes for profiling specific points */
function wfGetAllCallers() {
        return implode('/', array_map(
                create_function('$frame',' 
                        return isset( $frame["class"] )?
                                $frame["class"]."::".$frame["function"]:
                                $frame["function"]; 
                        '),
                array_reverse(debug_backtrace())));
}

?>